Treatment of hydrocarbon oils



Feb. 5, 1935.

J. C. MORRELL TREATMENT OF HYDROCARBON OILS Filed May 20, 1951 FRACTION/Woks 29 al J NSER,35

f In (as r37 1 s5 ['43 O 46 yr 56 RE VER F RACTIONATOR INVENTOR" JACQUE C. MORRELL lav/M 4456 ATTOR Y Patented Feb. is, 1935 I t 1,990,303

UNITEDSTATES PATENT OFFICE- v TREATMENT OF HYDROCARBON OILS Jacque C. Morrell, Chicago, 111., assignor to Universal Oil Products Company, Chicago, 111., a corporation of South Dakota Application May 20, 1931 Serial No. 538,698

' 4 Claims. (01.196-60) This invention relates to the treatment of hybeing thereby preheated by the relatively hot drocarbon oils and particularly refers to the convapors in this zone which it may assist to fracversion of relatively heavy oils into more valuationate and passing together with the relatively ble products of a lighter and lower boiling nature. heavy condensed components of the vapors 5 Primarily, the invention comprises subjecting through line 11 and valve 12 to pump 13 which 5 raw oil charging stock to relatively mild convermay supply the reflux condensate from this zone, sion conditions in a cracking system, subjecting alone or together with preheated raw oil, as the insufliciently converted intermediate products case may be, through line 14, valve 15 and line 7 from this conversion to further conversion under to heating element 8. Likewise, a portion or all more severe cracking conditions and returning 0f the raw Oil Charging Stock y, if d be 10 insufliciently converted intermediate products diverted from line 5 through line 16 and valve 17 resulting from the secondary cracking operation into fractionator 18 where it may assist fractionto reconversion in the primary cracking system. ation of the-vapors and from which it may pass A more specific embodiment of the invention together with their relatively heavy. condensed may comprise supplying raw oil charging stock components through line 19 and valve 20 to pump 15 to relatively mild conversion conditions in a 21. The reflux condensate from fractionator 18, heating element, introducing the heated oil into alone or together with preheated raw oil, as the an enlarged reaction zone in which vapors and casemay be, may be fed by means of pump .21 residual li'quid may be separated, subjecting the through line 22, valve 23 and lines 5 and '7 to 20 vapors to fractionation in a primary fractionatheating element 8. y

.' ing zone, reflux condensate from which may be The Oil pp d t0 heating element 8 y be returned to said heating element together with heated to the desired conversion temperature the raw oil charging stock, subjecting vapors under any desired pressure conditions byheat supfrom the primary fractionating zone to further p d' y y ab furnac The heated Oil 25 fractionation in a secondary fractionating zone, may be discharged through line 25 and valve 25 subjecting vapors from said secondary fraction- 26 into reaction chamber 27. Preferably, heating ating zone to condensation and cooling, and colelement 8 and chamber 27 are maintained under lecting the resulting products, subjecting residual a substantial supera p pressure and the oil from the reaction chamber to further vaporpressure employed in chamber 2'7 may bersub- 3O ization in a zone of reduced pressure, subjecting stantially the same or lower than that utilized vapors from said zone of reduced pressure ton the heat e e ent- D ay be Separated gether with reflux condensate from the aforefrom residual oil in chamber 2'7 and may be W mentioned secondary fractionating zone to furdrawn through line 28 and valve 29 to fractionather conversion, preferably under relatively setion in fractionator 18. The relatively heavy vere conversion conditions in a separate heating C DO tSO the V p Condensed in this Zone 35 element, introducing reconverted materials from are preferably .letumed, a already described. said separate heating element into a separate heating element8 for further conversion. Vapors fractionating zone, vapors from which may pass from fractionator 18 may P through line 30 t0 the r ned Secondary fractionating and valve 31 to further fractionation in fractionzone and reflux condensate from which may be ator 32. r o I returned to the first mentioned heating element The relatively lightfractionatedvaporsv of'the together with raw oil charging stock and reflux desired compositionmay pass from ct onation condensate fromthe primary fractionating zone. j h oi l n 33 and Valve y be Su The attached diagrammatic drawing illustrates jected to condensation and cooling in condenser one form of apparatus embodying the principles 35, distillate and uncondensable gas from which and features of the present "invention. The folmay pass through line 36-and valve 3'7to becol lowing description of the drawing embraces also lected in receiver 38. Uncondensable gas may be a description of theprocess of the invention as it released fromthe receiverthrough line '39 and may be practicedin the apparatus illustrated. valve 40. Distillate may be. withdrawn through:

Raw oil charging stock may lie-supplied through line 41 and valve 42. A portion of thedistillate- 50 line 1 and valve 2 to pump 3"from which it may I may, if desired, be recycledrby well known means be fed through line 4, line 5, valve 6, and line 7 (not shown) to any or all of the fractionators 32, intov heating element 8. lf desired, a portion or 18 and loto assist fractionation of the vapors: all of the raw oil charging stock may be fed in these respective zones.

5 through valve 9, in line 4, into fractionator 10, Residual oil may be withdrawn from chamber 27 through line 43 and valve 44 to chamber 45 which is preferably maintained under a substantially reduced pressure relative to that employed in chamber 27 and wherein the residual oil may be subjected to further vaporization. The final residual liquid product, if such is produced, may be withdrawn from chamber 45 through line 46 and valve 47. If desired, conditions may be so controlled in chamber 45 that only substantially dry coke or carbonaceous material will remain as the residual product and this may be collected in the chamber to be removed after the operation of the process is discontinued. If desired, a plurality of such chambers (not shown) may be employed for non-residuum operation and may be operated alternately or simultaneously to permit prolonged operation of the process. Vapors from chamber 45 may pass through line 48 and valve 49 to pump 50 from which they may be fed through line 51 and valves 52 and 53 into heating element 54. In case a substantially higher pressure is utilized in chamber 45 than that employed in heating element 54, pump 50 may be by-passed by directing the vapors through line 63 and valve 64, valves 49 and 52 being closed. The relatively heavy insuiiiciently converted components of the vapors which are subjected to fractionation in fractionator 32 may be condensed in this zone, may pass through line 55 and valve 56 to pump 57 from which they may be fed through line 58 and valve 59 into line 51, commingling therein with the vapors from chamber 45 and passing therewith to heating element 54.

Heating element 54 may be located within any suitable form of furnace 60 and the oil passing therethrough may be heated to the desired conversion temperature under any desired pressure conditions. Preferably more severe conversion conditions are employed in heating element 54 than those utilized in heating element 8 and, if desired, conditions withinthe range of vaporphase cracking may be utilized. Heated products may be discharged from the heating element 54' through line 61 and valve 62 into the lower portion of fractionator 10 in which any heavy polymerization products or the like may be separated from the vapors. Liquid accumulating in fractionator 10 which may comprise the relatively heavy condenser components of the vapors subjected to fractionation in this zone, any residual liquid or polymerization products and preheated raw oil,

if any portion of the raw oil is supplied to this zone, may be returned as already indicated through line 11, valve 12, pump 13, line 14, valve 15 and line 7 to heating element 8. Fractionated vapors from fractionator 10 may pass through line 63 and valve 64 to fractionator 32 to be subjected to further fractionation and the same subsequent treatment as that aflorded the vapors from fractionator 18.

Pressures employed within the system may range from substantially atmospheric to superatmospheric pressures as high as 2,000 pounds per square inch, or more. Conversion temperatures employed may range from 800 to 1200 F., more or less. Preferably substantial superatmospheric pressures of the order of 100 to 500 pounds per square inch are employed in the heating element and reaction chamber of the primary or rliquidvapor-phase system, while the conversion temperatures in the heating element of this system may range from 850 to 950 F., more or less.

Pressures substantially equalized with that employed in the reaction chamber or reduced pressures of the order of substantially atm0$- pheric to 100 pounds per square inch superatmospheric pressure, or thereabouts may be employed in the fractionating, condensing and collecting equipment of the system. Reduced pressures ofthe order of substantially atmospheric to 60 pounds per square inch, or more, superatmospheric pressure are preferably employed in the residuum flash distilling chamber. The secondary or vapor-phase conversion system preferably employs pressures of the order of substantially atmospheric to 150 pounds per square inch superatmospheric pressure and conversion temperatures of the order of 950 to 1200 F., more or less.

As a specific example of the operation of the process of the present invention, as it may be practiced in an apparatus such as illustratedand described, a 24 A. P. I. gravity fuel oil is the raw oil charging stock and it is subjected together with reflux condensate from the primary fractionator and reflux condensate from the fractiqnator of thevapor-phase system to a temperature of approximately 910 F. under a superatmospheric pressure of about 250 pounds per square inch. This pressure is substantially equalized within the reaction chamber and primary i'ractionator, is reduced in thesecondary fractionator to a pressure of about 100 pounds per square inch and in the residuum flash distilling zone to a pressure of about 30 pounds per square inch. Reflux condensate from the secondary fractionator and vapors from the flash distillation of the residual oil are subjected to a temperature of approximately 1050 F. under a superatmospheric pressure of about 100 pounds per square inch.

This operation may yield approximately of motor fuel having an anti-knock value approximately equivalent to a blend of 60% benzol and 30% straight-run Pennsylvania gasoline. In addition about 23% of marketable fuel oil may be produced, the only other products of the process being rich uncondensable gas and a small percentage of coke or carbonaceous material.

I claim as my invention:

1. A hydrocarbon oil cracking process which comprises subjecting the oil to cracking conditions of temperature and pressure in a cracking zone and separating the same into vapors and unvaporized oil, subjecting the vapors to primary and secondary dephlegmation thereby forming relatively heavy and light reflux condensates, retumi'ng the heavy reflux condensate to said cracking zone for retreatment therein, flash distilling the unvaporized ofl by pressure reduction, combining resultant flashed fractions with the light reflux condensate and cracking the mixture in a second cracking zone maintained at higher cracking temperature than the first-mentioned cracking zone, dephlegmating the vapors formed in said second cracking zone, and returning resultant reflux to said first-mentioned cracking zone, and finally condensing the dephlegmated vapors.

2. A hydrocarbon oil cracking process which comprises subjecting the oil to cracking conditions of temperature and pressure in a cracking zone and separating the same into vapors and unvaporized oil, subjecting thevapors to primary and secondary 'dephlegmation thereby forming relatively heavy-and light reflux condensates, returning the heavy reflux condensate to said cracking zone for retreatment therein, flash distilling dephlegmating the vapor phase cracked vapors and returning resultant reflux to said first-mentioned cracking zone, and flnally condensing the relatively heavy and light reflux condensates, re-

turning the heavy reflux condensate to said cracking zone for retreatment therein, flash distilling the unvaporized oil by pressure reduction, combining resultant flashed fractions with the light reflux condensate and cracking the" mixture-in a second cracking zone maintained at higher cracking temperature than the first-mentioned cracking zone, dephlegmating the vapors formed in said second cracking zone, and returning resultant reflux to said first-mentioned cracking zone, further dephlegmating the last-named vapors in admixture with the vapors undergoing secondary dephlegmation whereby the lighter insufliciently cracked fractions thereof are added to said light reflux condensate.

4. A hydrocarbon oil cracking process which comprises subjecting the oil to cracking conditions of temperature and pressure in a cracking zone and separating the same into vapors and unvaporized oil, subjecting the vapors to primary and secondary dephlegmation thereby forming relatively heavy and light reflux condensates,

returning the heavy reflux condensate to said cracking zone for retreatment therein, flash distilling the unvaporized oil by pressure reduction, subjecting the flashed vapors to vapor phase cracking in admixture with the light reflux'condensate,jdephlegmating the vapor phase cracked vapors and returning resultant reflux to said flrstdensate.

JACQUE C. MQRREIL. 

